<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .tab ul{
            overflow: hidden;
            padding: 0;
            margin: 0;
        }
        .tab ul li{
            box-sizing: border-box;
            padding: 0;
            float: left;
            width: 100px;
            height: 45px;line-height: 45px;
            list-style: none;
            text-align: center;
            border-top: 1px solid blue;
            border-right: 1px solid blue;
            /* cursor: pointer; */
        }
        .tab ul li:first-child{
            border-left: 1px solid blue;
        }
        .tab ul li.active{
            background-color: orange;
        }
        .tab div {
            widows: 500px;
            height: 300px;
            display: none;
            text-align: center;
            font-size: 30px;
            line-height: 300px;
            border: 1 solid blue;
            border-top: 0px;
        }
        .tab div.current{
            display: block;
        }
    </style>
</head>
<body>
    <div id="app">
        <div class="tab">
            <ul>
                <li v-on:click="change(index)" :class="currentIndex == index?'active':''" :key="item.id" v-for="(item,index) in list">{{item.title}}</li>
            </ul>
            <div :class="currentIndex == index?'current':''" :key="item.id" v-for="(item,index) in list">
                <img :src="item.path" alt="">
            </div>
        </div>
    </div>
    <script src="js/vue.js"></script>
    <script>
        var vm = new Vue({
            el:'#app',
            data:{
                currentIndex:0,//当前选项卡索引
                list:[{
                    id:1,
                    title:'apple',
                    path:'img/apple.png'
                },
                {
                    id:2,
                    title:'orange',
                    path:'img/orange.png'
                },
                {
                    id:3,
                    title:'lemon',
                    path:'img/lemon.png'
                }]
            },
            methods:{
                change:function(index){
                    //实现选项卡切换
                    //如何操作类名
                    this.currentIndex = index;
                }
            }
        })
    </script>
</body>
</html>